The present invention relates to a circuit board arrangement for electronic/electromechanical devices having a mechanically actuable switch for at least two different line voltages of an apparatus power supply unit.
For switching from an apparatus voltage present in one country to a different voltage (e.g. from 220 V to 110 V), so-called voltage-selection switches are customary. Such switches, however, are relatively expensive and arranged in a housing and are therefore expensive to manufacture.
An object of the present invention is to simplify voltage-selection switches of the expensive, conventional type and to assure their economical manufacture.
The foregoing object is achieved in accordance with the invention in the manner that a polygonal cutout is provided in a circuit board, the edge of which forms straight polygon sides. Each polygon side has a contact surface associated with it, each of which surfaces is connected to an electrical conductor of the apparatus power supply unit, with two opposite contact surfaces corresponding to one voltage potential, and that there can be introduced into the cutout a contact spring which has spring legs associated with the contact surfaces to contact them. This solution is extremely simple and economical and avoids the disadvantages of a closed voltage-selection switch housing. Thus a contact spring can be produced at a very low cost. Furthermore, more than two voltage steps can be covered in accordance with this principle.
One embodiment of the invention involves the spring legs extending through the cutout, and on one side contacting the contact surfaces and on the other side forming a U-shape. This development of the contact springs assures dependable retention in the circuit board.
Another improvement of the invention relates to locking, or securing, the contact springs onto the circuit board. For this purpose, a respective splay arm is formed in each of the spring legs of the contact springs. The splay arms may be formed by making cuts in the spring legs so that the resulting splay arms rest against the side of the circuit board opposite the contact surfaces in the installed condition of the contact springs.